Bonnie, you certainly have my prayers, warmest thoughts and wishes for a recovery.
My husband's cancer was also clear at his PET for BOT and we were totally thrown to hear that it was in his axilla. Especially since there was no sign of it on any previous PET.
They removed the cancer surgically but for good measure are doing radiation(and possibly chemo). They are still discussing the plan.
I know it's not the same as mets to the lungs. But we were told what other people mentioned. They are doing the radiation/chemo because they know he responded well to the treatment already. Keep in mind not everyone does. So, there is a treatment possibility that your husband has already responded well to. That's a good thing.

I also think that 2-3 years while sounding shocking and is also 2-3 years that can bring incredible advancements to the cancer field. As you now know, new trials and options are regularly being found.
My dad died of pancreatic cancer 6 months after diagnosis. While still a very serious cancer there is an excellent chance he would have lived longer with better quality of life had he been diagnosed more recently.
Keep your attitude of fighting back and you have us all here to support you.